This invention is directed in general to electrostatographic reproduction apparatus utilizing a dielectric web supported by guide rollers for movement along a travel path in relation to electrostatographic process stations, and more particularly to an assembly for cleaning the dielectric web of such electrostatographic reproduction apparatus.
In electrostatographic reproduction apparatus, it is general practice to provide a dielectric member movable along a path relative to electrostatographic process stations. For example, the dielectric member may be a web supported and guided for movement along the path by rollers. In such process stations, a uniform electrostatic charge is applied to the dielectric member web and such charge is modified in an area of the web to form, in such area, a charge pattern corresponding in imagewise fashion to information to be reproduced. The charge pattern is then developed by applying pigmented marking particles to the web. The particles, which are charged to a polarity opposite to that of the charge pattern on the dielectric member web, adhere to the pattern to form a developed image on the web. The developed image is then transferred to a final receiver member and fixed thereto by heat and/or pressure for example. After image transfer, the dielectric member web is cleaned to remove any residual marking particles prior to reuse of that area of the web.
Cleaning of the dielectric member web of such electrostatographic reproduction apparatus is accomplished by providing an assembly including a member which breaks the mechanical and electrostatic bond between the web and residual marking particles and sweeps the particles from the web. Typically, the cleaning assembly member is, for example, a rotating fur brush (such as shown in U.S. Pat. No. 4,213,794, issued July 22, 1980, in the name of Woodling et al), a rotating magnetic brush (such as shown in U.S. Pat. No. 4,501,484, issued Feb. 26, 1985, in the name of Shimura), or a resilient blade (such as shown in U.S. Pat. No. 4,690,544, issued Sept. 1, 1987, in the name of Fobes, II et al). While fur brush and magnetic brush cleaning members are very effective in providing for residual marking particle removal, there are of complicated construction, and are expensive to employ in the reproduction apparatus. Although less efficient in residual marking particle removal, the resilient sweeper blade is, on the other hand, of simple relatively inexpensive construction.
Accordingly, in electrostatographic reproduction apparatus designed for low volume usage, the resilient blade has been the cleaning assembly member of choice. This is because its simplicity of construction and minimum component cost is of prime importance. Moreover, at lower volume usages, the cleaning efficiency of resilient blades is sufficient to yield acceptable quality reproductions. The resilient blade cleaning assembly member, however, does present a unique potential problem due to its necessary pressure engagement with the dielectric member web to provide minimally acceptable cleaning efficiency. That is, it has a tendency to provide an undue constraint on the web moves in contact with the blade. This results in a potential adverse effect on proper tracking of the web as the web travels about its path relative to the electrostatographic process stations.